JP4092233B2 - Synthetic resin material cutting and feeding device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a synthetic resin material supply device that cuts and holds a molten synthetic resin extruded from an extrusion nozzle and supplies it to a predetermined position.
[0002]
[Prior art]
Conventionally, when molding a metal cap liner or a synthetic resin cap or container, after melting and kneading the synthetic resin material, the synthetic resin material extruded from the extrusion nozzle is molded with a molding device, A synthetic resin product having a predetermined shape is often obtained. As a synthetic resin supply apparatus for supplying such a synthetic resin material to a molding apparatus, in the invention described in Japanese Patent Laid-Open No. 2000-108127 (Patent Document 1), the synthetic resin material extruded from an extrusion nozzle is cut. The synthetic resin material cut by the holding means is held and transported, and the synthetic resin material cut at the discharge position is opened, freely dropped, and supplied to a predetermined position.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-108127
[Problems to be solved by the invention]
However, in such a synthetic resin material supply device, since the synthetic resin material is freely dropped and supplied at the discharge position, the discharged synthetic resin material does not fall at an appropriate timing and shifts from a predetermined position. May be placed. When molding is performed by pressing a mold or the like from above the synthetic resin material that is displaced, a part where the mold or the like cannot be pressed on the synthetic resin material may occur, and reliable molding may not be performed. there were.
[0005]
In addition, since the supply is performed by free fall, the shape or form after supply is not stable, and there is a possibility that the molding in the next process may be hindered. In other words, if the synthetic resin material is supplied in a distorted shape such that small pieces such as burrs and folds are formed on the surface, a part of the synthetic resin material drops while adhering to the inner wall of the holding means, such small pieces. Since the heat capacity of the part is small, it tends to cool and harden before being pressed against the mold after it is supplied, and the cold and hardened part may remain as wrinkles on the surface of the synthetic resin molded with the mold. .
[0006]
The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide an apparatus that can supply a synthetic resin material to a predetermined position reliably and with a stable shape.
[0007]
[Means for Solving the Problem and Action]
In order to achieve the above-mentioned object, the invention of claim 1 is to cut out the synthetic resin material in a molten state extruded from the extrusion nozzle from the opening end of the extrusion nozzle and cut out the synthetic resin material supplied to a predetermined location. In the supply device, the extrusion nozzle is extruded from the extrusion nozzle by having a cutting blade on a side facing the opening end of the extrusion nozzle and moving the side facing the opening end in a direction parallel to the opening surface. A cutting / holding member that cuts out the synthetic resin material and holds the cut-out synthetic resin material, and is disposed inside the cutting / holding member so as to be movable back and forth in the axial direction, and held in the cutting / holding member. and a discharge member for supplying extruding a resin material to a predetermined position, and more than 20% of the vertical projection plane with respect to the axial direction of the outer peripheral portion of the previous edge of the discharge member Moiety is an apparatus which is characterized in that is recessed in the axial direction.
[0008]
According to a second aspect of the present invention, the cutting / holding member according to the first aspect of the present invention is configured to move in a direction perpendicular to the central axis, and a part of the front side in the moving direction. The apparatus is characterized by forming a cylindrical shape in which a plurality of grooves are formed on the inner surface of the cylindrical shape.
[0009]
Therefore, according to the present invention, the synthetic resin material cut out by the cutting / holding member is pushed out to a predetermined position by the discharge member, so that the timing of dropping is caught by the holding portion and does not fit in the predetermined position. It is not supplied out of position. Therefore, the synthetic resin material cut out by the cutting / holding member can be reliably supplied to the predetermined position.
[0010]
The tip portion of the discharge member is retracted in the axial direction is 20% or more portions of the vertical projection plane with respect to the axial direction of the outer peripheral portion of the above end face. Therefore, when extruding the held synthetic resin material onto the object, there is no portion that rises in the form of a thin film or pleats in the periphery of the extruded synthetic resin material. It is possible to prevent the generation of burrs and pleats when molding in the next process.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described based on specific examples. FIG. 5 and FIG. 6 are schematic diagrams showing the overall configuration of the apparatus targeted by the present invention. The extrusion nozzle 9 is configured to extrude the molten synthetic resin material 5 from the extrusion nozzle opening 8. The holding part 1 is arranged on the upper part of the extrusion nozzle 9 so as to be movable in the horizontal direction. In addition, a metal plate such as an aluminum alloy plate or a surface-treated steel plate is drawn at a predetermined position in the advancing direction of the holding unit 1 by a press or the like so that a circular top plate portion and a cylindrical skirt portion are cupped. A metal shell 6 that is integrally formed in a shape and processed appropriately such as a vent slit and a tamper epitaxial band after drawing is disposed with the top plate at the bottom, and the holding portion 1 is located at this position. Move up.
[0012]
FIG. 1 shows the holding unit 1. The semi-cylindrical holding portion 1 has a cylindrical shape above it, and an ejector pin 3 that can move in the vertical direction within the cylinder is formed therein. The outer diameter of the ejector pin 3 is slightly smaller than the inner diameter of the holding portion 1 and slightly larger than the inner diameter of the extrusion nozzle opening 8. Further, the tip surface of the ejector pin 3 is formed in a hemispherical shape. That is, the entire outer periphery side recedes in an arc shape from the tip center. Further, a gas ejection hole 4 is formed. In this embodiment, the ejector pin 3 has an outer diameter of 10.5 mm, the holding portion 1 has an inner diameter of 11.5 mm, and the extrusion nozzle opening 8 has an inner diameter of 9.5 mm.
[0013]
The holding portion 1 has a semi-cylindrical shape in which a part of the front side in the traveling direction is cut open, and is extruded in a semicircular shape below the inner surface so that the synthetic resin material 5 can be held by the holding portion 1. A drop-off preventing groove 2 having a substantially V-shaped longitudinal section is formed in parallel with the nozzle opening 8. In this embodiment, O.D. 1 mm width is 6 pieces. The shape of the drop-off preventing groove 2 is preferably extended in a direction substantially perpendicular to the axial direction of the holding portion 1, and may be continuous or discontinuous, and the vertical cross-sectional shape is rectangular or arcuate. There may be. Further, the inner surface of the holding portion 1 is formed substantially perpendicular to the extrusion nozzle opening 8, and the lower end of the inner surface of the holding portion 1 cuts the synthetic resin material 5 extruded from the extrusion nozzle opening 8. A cutting blade that can be used. The holding portion 1 corresponds to the cutting / holding member in the present invention.
[0014]
After the synthetic resin material 5 is melted and kneaded, it is fed from the substantially circular extrusion nozzle 9 to the extrusion nozzle opening 8. The synthetic resin material 5 extruded from the extrusion nozzle opening 8 is held in close contact with the semi-cylindrical holding portion 1 having an inner diameter slightly larger than the inner diameter of the extrusion nozzle opening 8, and further held from there. As the part 1 moves forward, the synthetic resin material 5 pushed out to the lower end of the inner surface of the holding part 1 is cut so as to be sheared by the cutting blade at the lower end of the holding part 1. The holding unit 1 holds the synthetic resin material 5 that has been extruded and cut and transports it to a predetermined position for discharging, that is, a position where the metal shell 6 is disposed. The plastic resin material 5 is placed on the metal shell 6 by being pushed out by the ejector pins 3.
[0015]
The ejector pin 3 has a hemispherical tip surface. Therefore, when the synthetic resin material 5 is spread on the metal shell 6 by the tip surface of the ejector pin 3, the spread synthetic resin material 5 is deformed into a smooth curved surface along the tip surface of the ejector pin 3. And it can prevent that small piece parts, such as a burr | flash and a pleat, generate | occur | produce in the outer peripheral part of the synthetic resin material 5. FIG.
[0016]
2 to 4 show the liner molding process. When molding the liner material on the metal shell 6, the formed metal shell 6 is transported with the top plate portion at the bottom, and after placing the synthetic resin material 5 at a predetermined position, Placed below (FIG. 2). Thereafter, the mold 7 is pressed against the synthetic resin material 5 from above (FIG. 3) and molded (FIG. 4). At this time, if the placed synthetic resin material 5 has a distorted shape in which small pieces such as burrs and folds are generated, or is not accurately pressed to a predetermined position in the metal shell 6, it is uniformly molded. In other words, the liner surface may be wrinkled at the time of liner molding, or the synthetic resin material 5 may not completely reach every corner of the mold and the liner having a predetermined shape may not be molded. As a result, there is a risk that the aesthetic appearance will be impaired, and if there are wrinkles or poorly formed parts in the part corresponding to the sealed part of the liner, poor sealing may occur.
[0017]
The synthetic resin material 5 extruded from the extrusion nozzle opening 8 is extruded by a predetermined amount and then cut by the movement of the holding unit 1. This cut synthetic resin material 5 has a ratio of height to diameter of approximately 1. : 1 is preferable. This is because if the height of the cut synthetic resin material 5 is too larger than the diameter, when the synthetic resin material 5 is discharged to a predetermined position, the discharged synthetic resin material 5 may be tilted without being placed in place. Or fall. Therefore, there is a possibility that the synthetic resin material 5 may adhere to unnecessary portions or the shape may become distorted.
[0018]
Further, if the diameter of the synthetic resin material 5 cut by the movement of the holding unit 1 is too larger than the height, the cut synthetic resin material 5 becomes difficult to be held by the holding unit, and is transported from the receiving position to the discharging position. In the meantime, the cut synthetic resin material 5 may fall off.
[0019]
Further, the gap between the lower surface of the holding unit 1 and the extrusion nozzle opening 8 is made as small as possible, and ideally zero. In this embodiment, O.D. 1 mm or less. Thus, when the synthetic resin material 5 is cut, the synthetic resin material 5 cut by the movement of the holding portion 1 and the synthetic resin material 5 remaining in the extrusion nozzle are surely not threaded. Can be cut. Therefore, the synthetic resin material 5 does not adhere to unnecessary portions of the metal shell 6 or a small piece portion is not generated on the surface of the synthetic resin material 5, and the appearance of the metal cap is impaired. It is possible to prevent the occurrence of wrinkles.
[0020]
It is preferable to form a drop-off / fall-off preventing groove 2 on the inner surface of the holding portion 1, so that the synthetic resin material is melted and softened only by bringing the synthetic resin material 5 into contact with the inner surface of the holding portion 1. Since 5 falls into and comes into close contact with the drop-off preventing groove 2 and becomes a resistance against gravity, the synthetic resin material 5 can be reliably prevented from free falling without using a complicated mechanism.
[0021]
The width, depth, and number of the drop-off preventing grooves 2 are appropriately changed depending on the weight, viscosity, and the like of the synthetic resin material 5 to be held. The width of the drop prevention groove 2 is preferably in the range of 0.05 mm to 0.2 mm. If the width of the drop prevention groove 2 is larger than 0.2 mm, the cut synthetic resin material 5 is too closely attached to the groove portion. When the synthetic resin material 5 cut by the movement of the holding unit 1 is supplied to a predetermined position, a part of the synthetic resin material 5 is deformed or remains attached to the groove. Therefore, the synthetic resin material 5 supplied to a predetermined position becomes an irregular shape, which may cause wrinkles after liner molding. On the other hand, if the width of the groove is smaller than 0.05 mm, the cut synthetic resin material 5 may fall off while the synthetic resin material 5 is held and transported by the holding portion.
[0022]
The depth of the drop-off prevention groove 2 is preferably in the range of 0.05 mm to 0.2 mm. If the depth of the drop-off prevention groove 2 is deeper than 0.2 mm, the synthetic resin material 5 is supplied to a predetermined position. At this time, the synthetic resin material 5 that has entered into the depth of the groove may be deformed or remain attached to the groove, resulting in an irregular shape, which may cause wrinkles after the liner molding. Conversely, if the width of the groove is shallower than 0.05 mm, the groove is less likely to be resistant to gravity, and the cut synthetic tree seed material 5 may fall off while the synthetic resin material 5 is being held in the holding portion 1. .
[0023]
In the step of holding the synthetic resin material 5 cut by the movement of the holding portion 1, the ejector pin 3 is positioned above such that it does not come into contact with the cut synthetic resin material 5. When it is discharged at the position, it moves downward, pushes down the synthetic resin material 5 held at its tip, and separates it from the holding part 1.
[0024]
FIG. 7 shows a state when the synthetic resin material 5 is pressed against the metal shell 6 at a predetermined position. When the holding part 1 is positioned directly above the metal shell 6, the synthetic resin material 5 is pushed down by the ejector pin 3 and discharged from the holding part 1. Then, the discharged synthetic resin material 5 is pressed against the approximate center on the inner surface side of the top portion of the metal shell. Then, compressed air is injected from the gas ejection hole 4 formed at the tip of the ejector pin 3 to reliably separate the ejector pin 3 and the synthetic resin material 5.
[0025]
If only part of less than 20% of the vertical projection plane with respect to the axial direction of the outer peripheral portion of the previous end face of the ejector pins 3 do not retract axially, a synthetic resin material 5 front end surface of the ejector pin 3 The synthetic resin material 5 that protrudes from the center surface of the tip of the ejector pin 3 is shaped so as to stand vertically along the side wall surface of the ejector pin 3, and the portion is a small piece portion such as a burr or fold. since it may become 20% or more portions of the vertical projection plane with respect to the axial direction of the outer peripheral portion of the previous end face of the ejector pins 3 is required to have retreated in the axial direction.
[0026]
If the diameter of the ejector pin 3 is too small compared to the diameter of the cut synthetic resin material 5, when the synthetic resin material 5 held in the holding portion is pushed down, the synthetic resin material 5 is surely pushed down directly below. I can't. Therefore, there is a possibility that the cut synthetic resin material 5 may be supplied at a position shifted from a predetermined position. Therefore, the diameter of the ejector pin 3 is preferably equal to or larger than the opening diameter of the extrusion nozzle opening 8.
[0027]
Furthermore, the gap between the ejector pin 3 and the inner wall of the holding part 1 should be as small as possible. When the synthetic resin material 5 extruded from the extrusion nozzle opening 8 is cut by the movement of the holding unit 1, the synthetic resin material 5 is biased in the direction opposite to the moving direction of the holding unit 1 and adheres to the lower part inside the holding unit 1. At this time, if the gap between the ejector pin 3 and the inner wall of the holding portion 1 is increased, a part of the synthetic resin material 5 enters the gap. Therefore, when the ejector pin 3 moves downward and the synthetic resin material 5 is discharged, the ejector pin 3 is discharged in an irregular shape, which may cause wrinkles during liner molding.
[0028]
The synthetic resin material 5 held in the holding portion 1 is pressed against the approximate center of the top plate portion of the metal shell 6 with the ejector pin 3, and thus the synthetic resin material 5 is fixed compared to the case where the synthetic resin material 5 is freely dropped. The synthetic resin material 5 can be reliably supplied to the metal shell 6 at a predetermined position at the timing.
[0029]
Further, at the discharge position, the holding portion 1 itself is moved downward and kept close to the predetermined position, so that the time difference until the synthetic resin material 5 pushed down by the ejector pin 3 reaches the predetermined position from the holding portion. Therefore, the synthetic resin material 5 can be reliably supplied to a predetermined position.
[0030]
The synthetic resin material used in the present invention is not particularly limited, and is an olefin resin such as polyethylene or polypropylene, a polyester resin such as polyethylene terephthalate or polybutylene terephthalate, an elastomer resin, a styrene resin, Known synthetic resins such as acrylic resins, nylon resins, vinyl chloride resins can be used. Among them, as the resin material for the cap liner that seals the container mouth, for example, a polypropylene resin having excellent heat resistance, an elastomer resin having excellent heat resistance, impact resistance, and sealing properties are used. Furthermore, a blend material of low density polyethylene and ethylene-propylene copolymer synthetic rubber, a blend material of polypropylene and styrene elastomer, a polyester elastomer, and the like can be suitably used. Further, these resins can appropriately contain a softener such as hydrocarbon oil, a pigment, a filler, a lubricant, and the like.
[0031]
Further, ejector pins 3 is not limited to the above embodiments, 20% or more portions of the vertical projection plane with respect to the axial direction of the outer peripheral portion of the previous end face of the ejector pins 3 is long retreats in the axial direction That's fine. For example, in the central portion of the tip of the ejector pin 3, a range of less than 80% of the projection plane perpendicular to the axial direction is a flat surface so that it recedes in an arc shape or a linear shape from the peripheral portion of the flat surface Anyway.
[0032]
【The invention's effect】
As described above, according to the present invention, since the held synthetic resin material is pushed out by the discharge member, the fall timing is not shifted. Therefore, the synthetic resin material can be reliably supplied to the predetermined position.
[0033]
Further, the tip portion of the discharge member, is retracted in the axial direction is 20% or more portions of the vertical projection plane with respect to the axial direction of the outer peripheral portion of the previous edge of the discharge member. Therefore, when the held synthetic resin material is pushed down at the front end surface of the discharge member and pressed to a predetermined position, the surface of the synthetic resin material is molded along the retracted portion of the front end surface. When the resin material is molded in the next step, the generation of wrinkles can be prevented.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an example of a holding unit according to the present invention.
FIG. 2 is an explanatory view before molding a liner when molding a liner material on a metal shell.
FIG. 3 is an explanatory view during liner molding when a liner material is molded into a metal shell.
FIG. 4 is an explanatory view after liner forming when a liner material is formed on a metal shell.
FIG. 5 is a schematic view before cutting a synthetic resin material, showing the overall configuration of the target apparatus according to the present invention.
FIG. 6 is a schematic view after cutting the synthetic resin material showing the overall configuration of the apparatus targeted by the present invention.
FIG. 7 is a view showing a state when a synthetic resin material is pressed at a predetermined position.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Holding part, 2 ... Drop-off prevention groove, 3 ... Ejector pin, 5 ... Synthetic resin material, 8 ... Extrusion nozzle opening part, 9 ... Extrusion nozzle.

Claims (2)

In the synthetic resin material cutting and supplying apparatus for cutting out the molten synthetic resin material extruded from the extrusion nozzle from the opening end of the extrusion nozzle and supplying it to a predetermined location,
A synthetic resin material extruded from the extrusion nozzle has a cutting blade on the side facing the opening end of the extrusion nozzle and moves the side facing the opening end in a direction parallel to the opening surface. A cutting and holding member for holding the cut and cut synthetic resin material;
A discharge member disposed inside the cutting / holding member so as to be movable back and forth in the axial direction, and pushing out and supplying the synthetic resin material held inside the cutting / holding member to a predetermined position; and cut-supply device of a synthetic resin material, characterized in that 20% or more portions of the vertical projection plane set back axially with respect to the axial direction of the outer peripheral portion of the previous facet.   The cutting / holding member is configured to move in a direction perpendicular to the central axis thereof, and has a cylindrical shape in which a part of the front side in the moving direction is cut open, and the cylindrical inner surface 2. A synthetic resin material cutting and supplying device according to claim 1, wherein a plurality of grooves are formed in the synthetic resin material.

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